Add "sample locations" feature to GrProcessor

src/gpu/glsl/GrGLSLProgramBuilder.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "glsl/GrGLSLProgramBuilder.h"
 
 #include "GrPipeline.h"
 #include "glsl/GrGLSLFragmentProcessor.h"
 #include "glsl/GrGLSLGeometryProcessor.h"
 #include "glsl/GrGLSLVarying.h"
 #include "glsl/GrGLSLXferProcessor.h"
 
 const int GrGLSLProgramBuilder::kVarsPerBlock = 8;
 
 GrGLSLProgramBuilder::GrGLSLProgramBuilder(const DrawArgs& args)
     : fVS(this)
     , fGS(this)
-    , fFS(this, args.fDesc->header().fFragPosKey)
+    , fFS(this)
     , fStageIndex(-1)
     , fArgs(args)
     , fGeometryProcessor(nullptr)
     , fXferProcessor(nullptr) {
 }
 
 bool GrGLSLProgramBuilder::emitAndInstallProcs(GrGLSLExpr4* inputColor,
                                                GrGLSLExpr4* inputCoverage,
                                                int maxTextures) {
     // First we loop over all of the installed processors and collect coord transforms.  These will
@@ skipping 256 matching lines @@
         delete fFragmentProcessors[i];
     }
 }
 
 void GrGLSLProgramBuilder::finalizeShaders() {
     this->varyingHandler()->finalize();
     fVS.finalize(kVertex_GrShaderFlag);
     fFS.finalize(kFragment_GrShaderFlag);
 
 }